Early life undernutrition and aggression in two mouse strains.

Early undernutrition was shown to be correlated with increased aggression in adult mice after isolation. This was significant in numbers of fights and shorter latency to fight in the DBA/2J strain. Lower 5HIAA in the brain after pretreatment with a monoamine oxidase inhibitor was found in the undernourished group.     

Apoptotic body engulfment by a human stellate cell line is profibrogenic

Hepatocyte apoptosis and stellate cell activation are both features of chronic liver diseases, but a relationship between these events has not been explored. In macrophages, engulfment of apoptotic bodies induces expression of transforming growth factor-beta (TGF-beta), a profibrogenic cytokine. We examined whether a similar response occurs in stellate cells. Fluorescently labeled hepatocyte apoptotic bodies were added to cultures of primary and immortalized human stellate cells. Stellate cells, but not hepatocytes, readily engulfed apoptotic bodies in a time-dependent manner as assessed by confocal microscopy. The activation of primary and immortalized human stellate cells after incubation with apoptotic bodies, as well as their fibrogenic activity, was indicated by an increase in alpha-smooth muscle actin (primary cells), TGF-beta1, and collagen alpha1(I) mRNA (primary and immortalized cells). The profibrogenic response was dependent upon apoptotic body engulfment, because nocodazole, a microtubule-inhibiting agent, blocked both the engulfment and the increase of TGF-beta1 and collagen alpha1(I) mRNA. As described in primary rodent stellate cells, up-regulation of collagen alpha1(I) mRNA was inhibited by a PI-3K inhibitor (LY294002) and a p38 mitogen-activated protein kinase inhibitor (SB203580) in LX-1 cells. In conclusion, these data support a model in which engulfment of hepatocyte apoptotic bodies by stellate cells leads to a fibrogenic response by eliciting a kinase-signaling pathway.     

Evaluation of dry and wet transported intravaginal swabs in detection of Chlamydia trachomatis and Neisseria gonorrhoeae infections in female soldiers by PCR

Screening women for sexually transmitted diseases (STD) in nonclinic settings is highly desirable because many infections are asymptomatic. This is especially true for military women, for whom logistical, social, and other job-related obstacles present barriers to accessing medical care. We assessed the accuracy of intravaginal swabs transported by mail in a wet versus a dry state for PCR (Amplicor CT/NG test) detection of chlamydia and gonorrhea infections in a cross-sectional study of 793 active-duty military women attending an STD clinic. PCR tests of vaginal swabs (wet and dry) were compared to local clinical methods used on cervical swabs. Standard wet vaginal swab PCR testing detected more chlamydia (11.6%) than cervical enzyme immunoassay (9.3%). For detection of chlamydia using wet swabs, the sensitivity and specificity compared with adjudicated true positives were 94.6% (87 of 92) and 99.3% (696 of 701), respectively. Comparing dry swabs to true-positives for chlamydia, the sensitivity was 91.3% (84 of 92) and the specificity was 99.3% (696 of 701). Standard wet vaginal swab PCR detected more gonorrhea (3.3%) than routine cervical culture (2.1%). The sensitivity and specificity of PCR testing of wet swabs compared to true-positives (infected patients) were 96.3% (26 of 27) and 98.2% (752 of 766) for gonorrhea, respectively. For gonorrhea, the sensitivity and specificity of dry swabs compared to true-positives (infected patients) were 88.9% (24 of 27) and 98.3% (753 of 766), respectively. PCR testing of wet and dry transported intravaginal swabs to detect chlamydia and gonorrhea infections was an accurate diagnostic method for military women.     

Regaining chondrocyte phenotype in thermosensitive gel culture

Chondrocyte tissue engineering continues to be a challenging problem. When chondrocytes are duplicated in vitro, it is imperative to obtain an adequate number of cells of optimal phenotype. A temperature-sensitive polymer gel, a copolymer of poly(N-isopropylacrylamide) and acrylic acid (PNiPAAm-co-Aac), has the ability of gelling at 37 degrees C (the lower critical solution temperature, LCST) or above and liquefying below that temperature (Vernon and Gutowska, Macromol. Symp. 1996;109:155-167). The hypothesis of this study was that chondrocytes could (1) duplicate in the copolymer gel; (2) regain their chondrocyte phenotype; and (3) be easily recovered from the gel by simply lowering the temperature below 37 degrees C. Chondrocytes from adult rabbit scapular cartilage were harvested and cultured in a monolayer culture until confluency (approximately 2 weeks). Next, the cells were harvested and seeded into the copolymer gel and cultured for 2-4 weeks. The phenotype of the cultured cells was then characterized. Two groups of control cultures, monolayer and agarose gel, were used to compare their ability to maintain chondrocyte phenotype. The results showed that chondrocytes isolated from rabbit scapula can re-express chondrocyte phenotype in agarose culture and polymer gel culture but not in monolayer culture. Also, cultured chondrocytes can be easily recovered from polymer gel culture by simply lowering the temperature. This new in vitro method of chondrocyte culture is recommended for chondrocyte propagation and regaining chondrocyte phenotype before cell seeding or transplantation.     

Pertussis: the disease and new diagnostic methods.

Bordetella pertussis, the causative agent of whooping cough, produces an acute and chronic respiratory infection in infants and young children. B. pertussis is still a major health problem of young children throughout the world even though effective immunization against whooping cough is available. While predominantly a childhood disease, it has been reported also to be a cause of persistent cough in adults. This review discusses the numerous bacterial virulence factors that may play roles in the pathogenesis of pertussis and in immunity to infection. The present problems with pertussis diagnosis, recent advances, and future prospects for new and improved rapid diagnostics tests also are explored.     

Maternal heterozygosity for a mitochondrial trifunctional protein mutation as a cause for liver disease in pregnancy

Acute fatty liver of pregnancy (AFLP) and hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome are serious complications of pregnancy associated with significant maternal and perinatal morbidity and mortality. In previous reports, we have documented an association between AFLP and fetal deficiency of long-chain 3-hydroxyacyl coenzyme A dehydrogenase (LCHAD) [N. Engl. J. Med. 340 (1999) 1723-1731; JAMA 288 (2002) 2163-2166]. LCHAD activity resides in the alpha-subunit of the mitochondrial trifunctional protein (MTP), a complex protein that catalyzes beta-oxidation of long chain fatty acids. In all reported cases, the fetus carried a common alpha-subunit MTP mutation (G1528C, E474Q) on one or both alleles. However, the association between fetal LCHAD deficiency and the maternal HELLP syndrome has been limited. Here, we report a case history of a 27-year-old black female who underwent Cesarean section for placenta previa and fetal distress at 36 weeks gestation. The newborn was a healthy male child. Post-delivery, the mother developed severe HELLP syndrome with complications resulting in death of the patient. We used single strand conformation variance and nucleotide sequence analyses to screen DNA isolated from the mother and the newborn for mutations in the MTP alpha-subunit. The mother was heterozygous for a novel mutation (C1072A, Q322K) in exon 11 of the LCHAD domain of the MTP, while the fetal genotype was completely normal. We hypothesize that, in some cases, maternal heterozygosity for an MTP mutation maybe sufficient to cause the development of maternal liver disease without carrying an affected fetus. Combination of the metabolic stress of pregnancy and other environmental stresses may overwhelm the heterozygous mother's capacity for effective metabolism of long chain fatty acids, leading to an accumulation of potentially toxic fatty acid metabolites in the maternal circulation with subsequent damage to the maternal liver.     

Characterization of antimicrobial resistance among Escherichia coli O111 isolates of animal and human origin

Fifty isolates of Escherichia coli serogroup O111 recovered from humans and various animal species over a 24-year period (1976-1999) were examined for typical virulence-associated factors and susceptibilities to antimicrobials of human and veterinary significance. Nine H (flagellar) types were identified including nonmotile (n = 24), 32 (n = 12), negative (n = 5), and 56 (n = 3). Thirty-five (70%) isolates possessed at least one Shiga-toxin-producing E. coli (STEC)-associated virulence determinants (eae, stxl, stx2, hlyA) via PCR analysis. Of these 35 isolates, 20 possessed eae, stxl, and hlyA genes, whereas three isolates possessed eae, stxl, stx2, and hylA genes. Multiple antibiotic resistance was observed in 70% of the 50 E. coli O111 isolates. The majority of isolates displayed resistance to streptomycin, sulfamethoxazole, tetracycline, and kanamycin. Bacterial resistance to ampicillin, gentamicin, chloramphenicol, trimethoprim and apramycin was also observed. Integrons were identified in 23 (46%) of the E. coli isolates assayed, with a 1-kb amplicon being most frequently observed. DNA sequencing of these integrons revealed the presence of the aadA gene, encoding resistance to streptomycin. Two integrons of 1.5 and 2 kb contained the aadA2 and either dfrI or dfrXII genes, encoding resistance to streptomycin and trimethoprim, respectively. Integrons were also identified from isolates dating back to 1982. Isolates were further genetically characterized via ribotyping, which identified 15 distinct ribogroups, with 62% of isolates clustering into four major ribogroups. Certain riboprint patterns from different animal species, including humans, were observed in isolates spanning the 24-year collection period, suggesting the dissemination of specialized pathogenic O111 clones.